Communication systems are know to comprise a plurality of communication units, a limited number of communication resources (channels), an operator station, a communication resource controller, and a plurality of broadcast units. Such systems include trunked and conventional communication systems. Frequently, communication units that are functionally related to one another (i.e. separate law enforcement groups such as traffic enforcement, detectives, etc.) are grouped together to form a communication group. Communication groups can be further combined to create multi-communication groups (i.e. local and county-wide police departments). An operator, via the operator station, may select a communication group or a multi-communication group to receive a message transmission thus allowing many communication units to receive the message at substantially identical times.
However, as the size and complexity of such communication systems have grown to meet increasing user needs, the desire for increased multi-communication group capabilities has also grown. Current communication systems allow only one multi-communication group to be "open" at a time at a given operator station. That is, no more than one multi-communication group can be selected to receive a message at any time. The ability to select more than one multi-communication group would be useful when, for instance, there were multi-communication groups corresponding to law enforcement entities in the Northern, Southern, and Western regions of a state. If the operator receives an emergency call which requires an all points bulletin (APB) to be quickly sent to all three regions simultaneously, the operator requires the capacity to open more than one multi-communication group at the same time. The operator may also wish a particular public safety communication group, such as a local fire department, to be among the groups about to receive the APB. In addition, it is currently not possible to temporarily modify multi-communication groups prior to message transmission. Unfortunately, prior art communication systems cannot fulfill the needs of this type of operator.
Therefore, a need exists for a method which allows a plurality of multi-communication groups to be selected simultaneously and also allows multi-communication groups to be temporarily modified prior to message transmission.